I have one built already, but didn't get as detailed as this guy. Mine works great, and its amazing the gunk it strips off. I would not use it on coins. I tried a couple of sacrificial pennies, and although it cleans them the coin would be valueless after it comes out.

I have one built already, but didn't get as detailed as this guy. Mine works great, and its amazing the gunk it strips off. I would not use it on coins. I tried a couple of sacrificial pennies, and although it cleans them the coin would be valueless after it comes out.

If you want a "Were not fancy, but were cheap" test, you can use a battery and salt water bath, on a sacrificial coin in a cup. Getting the curcuit is tricky because if you use a alligator clip your going to get small points of erosion on the coin where it grabs. If you wrap the wire around the girth and pinch it off, it will hold the coin and there is no blemish on the faces, but the electroplating process that this is, removes metal from the face of the coin, damaging it